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Topic: Solenoids: Push and Pull?? (Read 10726 times)

Hi there, I'm new to this forum but I just wanted to know if anyone has heard of a solenoid (actuator) that is possible of being both push and pull, rather than the conventional push or pull. It says that it isn't possible to have such a thing on http://www.societyofrobots.com/actuators_solenoids.shtml , but was just wondering that if there was such a device, would it be of any use? because I've come up something that does both push and pull, and it doesn't use/contain springs, just magnets.

Ok first of all, I know what a linear actuator is, I went to that site as well, however if you look at the diagram, the sliding tube does move both in and out, but mine differs in that you have a solenoid, and the plunger enters one end, and exits the other. So instead of a plunger getting stuck in the middle because of the = but opposite forces, my plunger is able to pass right through. Whether or not my invention is better really depends on how useful it is to society and its market value. So far the ideas that I've come with are good, but they need alot more work. And finally no, it ain't two solenoids, just the one, and there are no springs. Another thing that makes it unique is that if you compare it to normal solenoid locks, which require power to either stay locked or open, my design doesn't. So if you lock it, then you only use power to initiate the lock, not to keep the lock locked, likewise when its open.

I haven't got any firm specs on it yet, the model that i got built was only designed to test my theory, all I know is that it can work/move in the horizontal plane of 3V, and about 12V in the vertical plane. The plunger is a special design and it uses rare earth magnets. The solenoid 30m of winding, so the actual solenoid isn't very powerful, im pretty sure that if I had more windings, shrunk the design down, it should run at less than 1V. In terms of torque, I haven't figure that out yet (I'm a 2nd yr Science student with majors in Biochm & Developemental Biology, only did Physics 101!!), so I'm waiting for my mech. eng. friend to figure it out. Trossen Robotics has actuators. that isn't what I have, actuators have motors & gears, mine doesn't. So no it ain't an actuator that moves really fast, it's something else that can move really fast.In terms of ideas, so far I've thought of: next gen solenoid lock, car engine, e-gun.

im pretty sure that it could be made with a regular magnet althoug the power would decrease over time. I should imagine that if you add more turns on the coil, it would allow more torque but only because it would allow more voltage.It might be worh looking at trying to make the same thing but with an electromagnet in the centre as well, an initial design would probably use brushes like motors do, but if you could use ball bearings to centre the plunger, you could send the electricity through them.

Its pretty pointless posting up pics because you can't actually see it work. Even if I made a video, you still couldn't see very well, you need to see it for real. In terms of putting an electromagnet inside, it would be good in theory, but it wouldnt be practical unless u required high amounts or torque. Besides that, I still haven't seen any posts in regard to its use! Which is kinda the 1st question to this topic.

OK, so my invention does have some uses. I'll try and see if modify the plunger to use electromagnets rather than the rare earth magnets. Btw, what's reasonably priced? I from Australia and well they don't really have many robotics shops around, even at uni. Thanks for the ideas, I'll keep you guys posted if anything interesting turns up.

Actually, what you're talking about is a "voice coil" which is short for "voice coil linear motor." It uses a modulated electromagnet and a centering spring to position a plunger at an offset from the center point; this offset can be positive or negative.

my design is very different than a voice coil motor it would not need a position sensor or driver and needs no springs, but could be setup with a position sensor. mine has more than double the force of a standard plunger solenoid.